[3.3.1 - Override] Fix annoying IE error

I have identified some of the random bugs :
- animation sometime failed as the required element sometime is not available (The code base do not check if the element exists or not, see fxUnwrap)
- IE randomly hate syntax like this (found in ExtJS code base) :
var d = this.dom, type = typeof d[ns+':'+name];

So I've create an override that fix thoses things, hoping it will help you kick the IE in the asses :